Arginine vasopressin levels are elevated and correlate with functional status in infants and children with congestive heart failure.

BACKGROUND Arginine vasopressin (AVP) is a vasoactive hormone that acts on the kidney to conserve solute-free water and produces a potent vasoconstrictive effect during hypovolemic states. AVP levels are elevated in adults with congestive heart failure (CHF), and early clinical trials using AVP antagonists are being conducted. The purpose of this study was to determine if AVP levels (1) are elevated in children with CHF attributable to left ventricular dysfunction or pulmonary overcirculation attributable to large left-to-right shunts and (2) can predict functional clinical status. METHODS AND RESULTS AVP levels were measured in patients with dilated cardiomyopathy (DCM) and CHF and in patients with large left-to-right intracardiac shunts. Each patient with DCM (ejection fraction percent <40%) was classified as NYHA functional class I through IV when the AVP level was drawn. Serum sodium was measured, serum osmolality was calculated, and echocardiograms and chest radiographs were performed on all study patients. AVP levels were also measured in age-matched controls. Mean AVP level in children with DCM (n=27) was 10.3 pg/mL (+/-12.8) versus 3.7 pg/mL (+/-2.4) in controls (n=15) (P<0.01). Mean AVP level in children with left-to-right shunts (n=14) was 13.9 pg/mL (+/-17.3) versus 3.5 pg/mL (+/-1.3) in controls (n=8) (P<0.04). In patients with DCM, AVP levels correlated directly with NYHA functional class (r2=0.73, P<0.001). CONCLUSIONS Arginine vasopressin levels are elevated in infants and children with CHF attributable to left ventricular dysfunction and in infants with large left-to-right intracardiac shunts. Furthermore, there is a direct relationship between AVP level and the severity of heart failure in patients with DCM.